This invention relates generally to gas turbine engines, and more specifically to methods and apparatus for operating gas turbine engines.
Gas turbine engines generally include, in serial flow arrangement, a high-pressure compressor for compressing air flowing through the engine, a combustor in which fuel is mixed with the compressed air and ignited to form a high temperature gas stream, and a high pressure turbine. The high-pressure compressor, combustor and high-pressure turbine are sometimes collectively referred to as the core engine. At least some known gas turbine engines also include a low-pressure compressor, or booster, for supplying compressed air to the high pressure compressor.
Gas turbine engines are used in many applications, including in aircraft, power generation, and marine applications. The desired engine operating characteristics vary, of course, from application to application. More particularly, within some applications, a gas turbine engine may include a single annular combustor, including a water injection system that facilitates reducing nitrogen oxide (NOx) emissions. Alternatively, within other known applications, the gas turbine engine may include a dry low emission (DLE) combustor.
Intercooler gas turbine engines may include either the single annular combustor, a can-annular combustor, or the DLE combustor, however, injecting water into such an engine to facilitate reducing NOx emissions, may actually decrease the operating efficiency of the gas turbine engine. Moreover, although using an intercooler facilitates increasing the efficiency of the engine while reducing the quantity of work performed by the high pressure compressor, the heat rejected by the intercooler is not utilized by the gas turbine engine.